How do I download printer software if I don't have a CD/DVD drive?

The new MacBook Pro doesn't have a built in CD/DVD drive, which seems to be the way computers are going as they get sleeker. I would think that printers would be keeping up with this, as Microsoft has (just a code to download Office) but can't find it on the Canon website. I have a Pixma MG3220. If anyone can point me in the direction of downloads, that would be great. I went to Support under Drivers and Software but there's only an explanation of what they do and no place to download.